Demos by PIRA

5K10 Induced Currents and Forces


  5K10.10Elementary generator: Bar moved in magnetic field.
  5K10.20Bar magnet induces current in a coil, shown on galvanometer.
  5K10.24Demonstration of dependence of number of coils on induced flux
  5K10.60Earth inductor: Coil spun in Earth's field makes voltage.

5K20 Eddy Currents


  5K20.10Damped pendulum: Swinging metal disks damped in magnetic field.
  5K20.25Eddy currents: Neodymium Magnet Drop.
  5K20.25Eddy currents:Small magnet slowly drops between aluminum rails.
  5K20.30Jumping rings: High current AC coil causes rings to jump.
  5K20.41Levitator: Aluminum dish floats four inches off platform.

5K30 Transformers


  5K30.25Demountable transformer with many secondary coils from 10:1 to 1:46.
  5K30.40Same as above: Secondary used for spot-welding.
  5K30.40Same as above: Secondary used for induction melting.

5K40 Motors and Generators


  5K40.10Rolling bar motor: Same as D+30+ 20.
  5K40.10Elementary split-ring armature DC motor. D+15+6 as a motor.
  5K40.20Generator: Coil with DC commutator rotates between magnets.
  5K40.20Alternator: Coil with AC commutator rotates between magnets.
  5K40.80Hand-cranked DC generator powers 120 volt lamp.
  5K40.80Hand-cranked AC alternator powers 120 volt lamp.